Amylase and protein in parotid saliva after load doses of different dietary carbohydrates

Abstract

Parotid saliva was collected from seven young women after a 12-hr fast and 1 and 2 hr after load doses of seven different carbohydrates and after water alone. Total protein, amylase activity, flow rate, protein patterns on polyacrylamide gel, and recovery of amylase activity from the gel were investigated. Amylase and total protein secretion increased 1 and 2 hr after the carbohydrate load dose and after water alone. The increase could not be attributed to the carbohydrate load doses. Correlation between amylase activity and total protein was highly significant. No correlation was found between flow rate and amylase activity or protein content in parotid saliva, or between flow rate and the different carbohydrate load doses. Parotid amylase activity and total protein secretion varied greatly, both among and within the seven subjects. Considerable variation was noted in the flow rate between the subjects, but the flow rate for each subject was relatively constant throughout the study. Unconcentrated parotid saliva separated on polyacrylamide gels typically showed six to seven protein areas with one major amylolytic area after 60 min of electrophoresis. The area containing amylase activity further separated into three to four bands after 120 min of electrophoresis. The number of protein bands on the gels, which varied from subject to subject, did not appear to be affected by the kind of carbohydrate administered in a load dose.